1. Field of the Invention
The invention relates to a contacting assembly for tapping and passing on a voltage, in particular a high frequency (HF) measuring tip or HF measuring probe, comprising a carrier on which a conductor structure is arranged, wherein the conductor structure has, at a contact end, at least one contact element protruding beyond an edge of the carrier for making electrical contact with at least one contact point of a device under test, and wherein the conductor structure has at least one impedance converter or impedance transformer.
2. Description of Related Art
Conventional contacting assemblies in the form of measuring tips are known, inter alia, from the publication DE 199 45 178 C2 and from the publication WO 2006/066676. In order to test the functionality and electrical properties of devices under test, for example in the form of electronic circuits arranged on wafers, measuring tips are usually used which are placed mechanically, with projecting contact elements, onto corresponding contact points of the electronic circuit being tested. Such electronic circuits which are to be tested also generate or process high frequency signals, so that the measuring tip also needs to take into account a corresponding (wave) impedance or characteristic impedance. In other words the measuring tip must display, at its contact end, an impedance adapted to the tested electronic circuit of the device under test, since otherwise, in the event of a mismatch, as is generally known, reflections can result which can influence a measurement result adversely or make a measurement impossible.
However, if a coaxial cable or a circuit with a specified impedance of for example 50Ω or another connecting element with specified impedance is connected at a connection end of the conductor structure opposite the contact end of the conductor structure for further transmission of the signals or voltages picked up from the device under test, it can be necessary to integrate an impedance converter in the conductor structure on the carrier, so that the measuring tip can be used to measure a device under test with different impedance without undesired reflections.
A passive component such as an RF transformer or another surface-mounted device (SMD) can be used as such an impedance converter. However, such an impedance converter can only be used for impedance transformation over a limited frequency range. If the HF signals originating from the device under test and passed through the measuring tip lie outside of this frequency band, undesired reflections are generated by the impedance converter.
WO 03/012461 A1 discloses a measuring arrangement for high frequency measurements using several measuring probes to make contact with conductor structures on wafers and similar. The measuring probes comprise free-floating coplanar contact tips which are fixed by means of at least one carrier in the vicinity of their contact end such that they have a fixed position relative to one another. The measuring arrangement according to WO 03/012461 A1 also has a conductor segment with narrowing or widening cross section designed in the form of an impedance transformer.